Abstract: A dimple magnetic recording head in a transducer assembly for linear tape drives haviang a flat transducing surface extending laterally a partial width of the magnetic recording tape is mass produced by lapping a row of transducers on a substrate to form a flat transducing surface. The row of substrate elements is then diced into separate substrate elements. Two parallel, spaced apart tape support surfaces are provided extending laterally the full width of the tape, and one of the diced substrate elements is mounted intermediate the tape support surfaces with the flat transducing surface exposed for forming a tape facing surface.

Abstract: A data storage library subsystem and a method for storing, and maintaining and tracking synchronism between, multiple copies of identifiable data volumes between hosts and a plurality of data storage libraries, and transparent to the hosts. The library controller of each library provides an updatable synchronization token directly associated with each data volume. A plurality of directors are provided, each separate from and coupled to the hosts and each separate from and coupled to each data storage library. Each director responds to ones of separate, partitioned access addresses addressed by the hosts. The responding director supplies each data volume supplied from a host to all of the data storage libraries, and updates each synchronization token directly associated with the supplied data volume. Thus, the directors store duplicate copies of the data volume in the data storage libraries without involvement by the host.

Abstract: A data storage library system and a method for storing, and maintaining and tracking synchronism between, multiple copies of identifiable data volumes between hosts and a plurality of data storage libraries, and transparent to the hosts. The library controller of each library provides an updatable synchronization token directly associated with each data volume. A plurality of directors are provided, each separate from and coupled to the hosts and each separate from and coupled to each data storage library. Each director responds to ones of separate, partitioned access addresses addressed by the hosts. The responding director supplies each data volume supplied from a host to all of the data storage libraries, and updates each synchronization token directly associated with the supplied data volume. Thus, the directors store duplicate copies of the data volume in the data storage libraries without involvement by the host.

Abstract: A method for forming a merged thin film magnetic head having a first shield layer and a combined second shield and bottom pole piece layer arranged in a sandwich supporting a read sensor therebetween at the pole tip region. The combined second shield and bottom pole piece layer are magnetically coupled with the first shield layer at the pole tip end of the yoke region adjacent the read sensor, and overlaying and magnetically coupled with the first shield layer at the back gap region. A patterned opening is provided in the combined second shield and bottom pole piece layer at the yoke region thereof to expose the first shield layer and form a flat planarization surface thereon. A plurality of stacked thin film coil layers are provided in the patterned opening, and a top pole piece layer overlies the thin film coil at the yoke region, overlies the bottom pole piece at the pole tip region providing a pole tip and gap thereat, and overlies the bottom pole piece at the back gap region.

Abstract: A method, apparatus, and a disk file for adjusting the height of a set of load/unload lift cams with respect to the axial height of an associated stack of disks. The method steps comprise supporting load/unload lift cams with an adjustment tool, measuring the relative height of the load/unload lift cams with respect to the stack of disks in the axial direction with a non-contact transducer, and fixing the load/unload lift cams at a registered height with respect to the stack of disks.

Abstract: In an optical data storage device for storing data on a removable optical disk in a continuous sequence of sectors or blocks, the input data buffer may be subject to under-run. An under-run detector is disclosed which is responsive to the buffered data comprising less than a sector of data for indicating an under-run, and a padding provider is disclosed which is responsive to the under-run indication for providing padding characters for formatting into sectors. The sectors may be provided with headers indicating the sectors as padding. A reading device for reading the data sectors and providing the data to a host detects padding and prevents the padding data from transmission to the host.

Abstract: Disclosed are a shared direct access data storage system and sharing method for use with both an MVS data processing system and a data processing system employing FBA data, for storing data set records received from the MVS data processing system. A CKD controller receives the data set from the MVS data processing system. An FBA controller and disk data storage provides direct access to FBA records by the FBA data processing system. A mapping element maps the data set records from the MVS data processing system into FBA data records with fixed blocks. The received data set records are uniformly sized, and the mapping element converts the uniformly sized records into smaller sized fixed blocks, with the size of the uniformly sized records being an even multiple of the smaller sized fixed blocks. A map translates the data of the first record of the data set into the block id of the first block and continues to map the data set into a continuing sequence of fixed blocks.

Abstract: Storage shelves of a mass data storage library are organized into a plurality of subsets for the purpose of conducting an inventory of media stored in the shelves. In response to an inventory command, the inventory is conducted in a predetermined order by subset. Upon completion of the inventory of each subset, the completion is posted in a list. A command input detects newly issued commands (subsequent to the inventory command), and places them in a queue. After completion of the inventory of a subset, and upon detecting a command for a non-inventory process (such as a media move), the inventory is interrupted and stopped. The move is conducted, and, upon completion of the move, the inventory is resumed. If a newly issued command is an inventory command, the inventory command is incorporated into the inventory process.

Abstract: In an optical data storage device for storing data on a removable optical disk in a continuous sequence of sectors or blocks, the input data buffer includes an ECC process. A padding provider is disclosed which is responsive to an under-run indication for providing padding characters for formatting the storage into sectors. The sectors may be provided with headers indicating the “padding sectors”. A reading device for reading the data sectors and providing the data to a host detects padding and prevents the padding data from being transmitted to the host.

Abstract: Disclosed are a method and a detector for adaptively detecting servo gaps in a timing based servo pattern prerecorded on a variable velocity media. The timing based servo pattern has groups of repeated pairs of non-parallel transition stripes arranged in bursts, the bursts separated by servo gaps whose length is variable. A servo system sensor senses the transition stripes in the longitudinal direction of the media. A group interval detector coupled to the sensor detects the timing interval between the same slope transition stripes of two sequential groups of bursts. A divider divides the detected group timing interval by a predetermined divisor to provide a divided timing interval gap detection threshold. A sequential stripe interval detector coupled to the sensor measures the timing interval between stripes, and a comparator compares the divided timing interval and the timing interval, identifying a servo gap upon the measured timing interval at least equaling the gap threshold.

Abstract: Disclosed are a method, a storage management system, an article of manufacture comprising a computer readable medium, and a computer program product for saving a recovery plan file for a storage management server. The storage management system has a plurality of storage management servers at sites remote from one another coupled by a server-to-server infrastructure. A recovery plan file is saved for one of the storage management servers at one of the sites by establishing the server as a source for its recovery plan file. Another storage management server at a site remote from the source server site is established as a target for the recovery plan file. The source server transmits the source recovery plan file from the source server to the target server at the remote site over the server-to-server infrastructure. The source recovery plan file is managed at the target server according to defined criteria, for placement, backup, migration and expiration under the control of the source server.

Abstract: A method, system, and computer program product for protecting data of a shared access data storage system from being overwritten, where the data storage system includes a device which is shared by separate hosts over at least two logically or physically distinct communication paths. An overwrite protection facility operates the data storage system controller processor independently of the hosts to automatically protect the device upon the occurrence of a write command for the device. The protection allows only the communication path issuing the write command, and communication paths in the same group as the issuing communication path, to issue commands resulting in movement of the media on the device. Commands not resulting in movement of the media are allowed from any communication path. The protection continues until specifically released by a “MEDIA REMOVAL” command. The protection, in one embodiment, is by means of a prime protected attribute for the device-communication path pair.

Abstract: Identifying most recent redundant copies of identifiable data volumes stored in a plurality of data storage libraries which are coupled to a plurality of directors. To update a data volume, an initiating director attempts to set a current token “inconsistent” flag to potentially down level copies of the data volume on each lagging library. Upon failing to receive notification of any successful setting of the current token “inconsistent” flag from any of the lagging libraries, the director forwards the request to the other directors, which attempt to set the current token “inconsistent” flag for the volume at any lagging library from which no notification has been received. Upon all of the other directors responding to the initiating director, and upon the other directors indicating failure to set the “inconsistent” flag at the lagging library, all the directors list the volume and a new token as an entry in a “hot token” list.

Abstract: A synchronous interface is provided for an asynchronous channel, for example, a read channel for a variable velocity magnetic tape, the channel providing asynchronous samples of an input signal from a fixed clock. The input signal, for example, comprises PRML data, written based upon synchronous write clock boundaries. The synchronous interface of the invention presents estimated synchronous samples at estimated write clock boundaries to allow decoding of the input signal. A phase estimator is coupled to the asynchronous channel for estimating the timing offset of the input signal synchronous write clock boundaries from the asynchronous samples. A sample estimator is coupled to the asynchronous channel and to the phase estimator for estimating, from two sequential asynchronous samples bounding an input signal synchronous write clock boundary, the input signal amplitudes at the estimated timing offset from the asynchronous samples.

Abstract: A method of handling eject requests of logical volumes received by a data storage subsystem from a host system. The method, implemented in computer readable program code, first places identified logical volumes in scratch categories. An eject request is received from a host system, to eject a logical volume from the data storage subsystem. The method responds to the eject request to determine whether the requested logical volume is in a scratch category; if the requested logical volume is determined as to be in a scratch category, a virtual media server is notified that the requested logical volume is deletable, and the virtual media server determines from its database whether the status of the requested logical volume allows deletion thereof. If the virtual media server status determining step allows deletion of the requested logical volume, the requested logical volume is deleted from both the virtual media server database and the library manager database.

Abstract: A detector and method for detecting data modulated into a timing based servo pattern prerecorded on a media, comprising shifts of pairs of non-parallel transition stripes arranged in a frame of two bursts. Timing intervals between sequential transition stripes are detected. Interval comparison logic compares selected timing intervals and indicates whether the compared intervals represent a “0”, or a “1”. First and second counters respectively increment the number of the compared intervals representing a “0” and representing a “1” in each frame. Bit comparison logic compares, for each frame, the incremented numbers representing a “0” and a “1” to a predetermined criteria and, upon one of the numbers meeting the criteria, identifies the corresponding “0” or “1” as the bit value for the frame. The bits are data comprising longitudinal position words arranged in a linear sequence.

Abstract: Disclosed are a subsystem and a method for diagnosing a fiber optic network, the fiber optic network comprising a fiber having an optic stream adhering to a defined protocol of the fiber optic network, and comprising a target for receiving and responding to the optic stream. The diagnosis comprises receiving the fiber optic stream and converting the fiber optic stream to an electrical input stream with a FOSA (fiber optic subassembly), and recognizing, from the electrical input stream, a selected event (e.g., frame or command) related to the optic stream defined protocol. Then, in response to the recognition of the selected event, recognizing a selected pattern of the electrical input stream, e.g., employing mask logic, and injecting, in response to the recognition of the selected pattern, a transmission error into the optic stream, and transmitting the optic stream with the injected transmission error to the target, employing a FOSA.

Abstract: Disclosed is a method, embodiable in computer readable program code in a network resource, for dynamically changing a network protocol management information base (MIB) module, the protocol requiring predetermined fixed fields in the MIB module. The method comprises inserting a variable in one of the predetermined fixed fields in the MIB module, and providing a first path for dynamically setting a reference to a script which substitutes for the variable, the referenced script defining a user option for operating the network resource. The referenced script operation may sense a value related to the network resource. A second path is provided to the script reference, whereby a query on the second path activates the script operation to provide the value at the MIB, and the provided value is delivered on the second path. The referenced script operation may additionally comprise conducting an operation of the network resource, and the value relates to the operation of the network resource.

Abstract: A suspension assembly with a pitch motion limiter, for a magnetic disk drive. The suspension comprises a load beam having a load/unload cam follower at a distal end, and having a load gimbal; a flexure mounted on the load beam, the flexure having a free end adjacent the load gimbal, and the flexure having a gimbal surface facing the load gimbal and having a head slider mounting surface opposite the gimbal surface for mounting a head slider having a trailing edge; and a pitch limiter for limiting the maximum pitch motion of the flexure free end with respect to the load beam. The pitch limiter comprises a pair of tabs on the load beam at opposite sides of, and aligned with, the load gimbal, and the tabs projecting in a direction perpendicular to the head slider trailing edge, and a pair of frames on the flexure at opposite sides of the load gimbal, each of the frames aligned with and completely surrounding a corresponding one of the tabs.

Abstract: Disclosed are a method, embodiable in computer readable program code, and a system for providing server-to-server event logging. A server-to-server event message is generated including 1) an event identifier, 2) any text insert pertinent to the event message, and 3) a source trail indicating the origin and history of the event, the source trail comprising an identifier of any server forwarding the event, each identifier separated by a special character, so that the origin and any subsequently transmitting servers may be known. Further, the source trail of a received server-to-server event message is parsed to determine each identifier in the source trail, and the event message transmitted to a receiving server only if the receiving server identifier is absent from the parsed source trail, thus preventing any loops which might cause the event to be repeated.